Method and apparatus for sidelink communication

Abstract

An operation method of a source terminal for sidelink communication comprises transmitting at least two transport blocks (TBs) or code block groups (CBGs) to a destination terminal, and receiving hybrid automatic repeat request-acknowledgement/negative acknowledgement (HARQ-ACK/NACK) bits for the at least two TBs or CBGs from the destination terminal. The operation method further comprises generating an HARQ codebook based on the HARQ-ACK/NACK bits, and reporting the generated HARQ codebook to a serving base station.

What is claimed is: 
     
         1 . A method of a source terminal in sidelink communication, the method comprising:
 receiving configuration information of configured sidelink resources from a base station;   transmitting a first physical sidelink shared channel (PSSCH) to a destination terminal through a first SL resource according to the configuration information;   receiving a negative acknowledgement (NACK) for the first PSSCH from the destination terminal; and   in response to the NACK for the first PSSCH, retransmitting the first PSSCH to the destination terminal through a second SL resource according to the configuration information.   
     
     
         2 . The method according to  claim 1 , wherein the configured sidelink resources are configured semi-persistently. 
     
     
         3 . The method according to  claim 1 , wherein the first PSSCH is retransmitted through the second SL resource when a second PSSCH to be initially transmitted to the destination terminal through the second SL resource is not selected. 
     
     
         4 . The method according to  claim 3 , wherein when the second PSSCH is not selected to be initially transmitted through the second SL resource, the second PSSCH is initially transmitted to the destination terminal through a third SL resource, the third resource is allocated based on the configuration information, and the third SL resource occurs later than the second SL resource. 
     
     
         5 . The method according to  claim 1 , wherein the retransmitting of the first PSSCH is indicated to the destination terminal through sidelink control information (SCI). 
     
     
         6 . The method according to  claim 5 , wherein the retransmitting of the first PSSCH is indicated to the destination terminal through a new data indicator (NDI), hybrid automatic repeat request (HARQ) process number identifier (ID), and/or redundancy version (RV) included in the SCI. 
     
     
         7 . The method according to  claim 1 , wherein the NACK for the first PSSCH is not reported by the source terminal to the base station. 
     
     
         8 . The method according to  claim 1 , further comprising: before the retransmitting,
 determining whether to select a second PSSCH to be initially transmitted through the second SL resource; and   in response to determining that the second PSSCH to be initially transmitted is selected, initially transmitting the second PSSCH through the second SL resource instead of the first PSSCH.   
     
     
         9 . A method of a destination terminal in sidelink communication, the method comprising:
 receiving a first physical sidelink shared channel (PSSCH) from the source terminal through a first SL resource according to configured sidelink resources;   transmitting a negative acknowledgement (NACK) for the first PSSCH to the source terminal; and   in response to the NACK for the first PSSCH, receiving the first PSSCH retransmitted from the source terminal through a second SL resource according to the configured sidelink resources.   
     
     
         10 . The method according to  claim 9 , wherein the configured sidelink resources are configured semi-persistently. 
     
     
         11 . The method according to  claim 9 , wherein the first PSSCH is retransmitted through the second SL resource when a second PSSCH to be initially transmitted from the source terminal through the second SL resource is not selected by the source terminal. 
     
     
         12 . The method according to  claim 11 , wherein when the second PSSCH is not selected to be initially transmitted through the second SL resource, the second PSSCH is initially transmitted from the source terminal through a third SL resource, the third resource is allocated according to the configured sidelink resources, and the third SL resource occurs later than the second SL resource. 
     
     
         13 . The method according to  claim 9 , wherein the retransmitting of the first PSSCH is indicated by the source terminal to the destination terminal through sidelink control information (SCI). 
     
     
         14 . The method according to  claim 13 , wherein the retransmitting of the first PSSCH is indicated by the source terminal through a new data indicator (NDI), hybrid automatic repeat request (HARQ) process number identifier (ID), and/or redundancy version (RV) included in the SCI. 
     
     
         15 . The method according to  claim 9 , wherein the NACK for the first PSSCH is not reported to the base station.